There exists, for example, a position light as having a light emission function. By using this function, a driver, a cyclist, a pedestrian, etc. can recognize the presence of another pedestrian at night and the like.
Concerning light emission control of such light function, Japanese Laid-open Patent Publication No. 2000-224287 discloses that when a user uses an operation section of a portable telephone to enter a luminescence start instruction or a luminescence end instruction, an incoming call notice section, a display section and the operation section are made to light up or to finish luminescence thereof, or the luminescence thereof are also made to be finished after an entered luminescence time has passed (Abstract, FIGS. 3, 4, etc.).
A position light has the main object of making others recognize the presence of oneself. This object differs from light emission of, for example, a penlight for lightening the dark by oneself. When a position light is turned on with using a battery, it is able to escape unnecessary power consumption if a switch, etc. that switches from/to light emission to/from extinction by manual is provided.
When a timer is set for the light emission control thus a light is turned on according to an inputted time (Japanese Laid-open Patent Publication No. 2000-224287), a position light cannot be turned on even under the situation where the light is necessary, such as going out at night, unless the time for turning the light on is inputted. Therefore, the function of a position light of making others recognize the presence of oneself results being spoiled.
In the timer setting for emitting a light according to an inputted time, light is emitted till the setting time has passed even if the light emission is unnecessary. Then, an extinction operation thereof is needed. If the extinction operation is forgotten, vain power consumption is generated. If the light is driven by a battery, there is inconvenience of draining the battery.
Concerning such problems, there is no disclosure or suggestion thereof in Japanese Laid-open Patent Publication No. 2000-224287, and no suggestion about the structure for solving them is presented.